Pregnancy is a vulnerable period in women's lives, with a range of maternal and environmental factors impacting upon pregnancy outcome. This study sought to explore the clustering of health risks among pregnant women, and compare the characteristics of women exhibiting clustered risks. A cross-sectional study was undertaken at a large public hospital in Queensland, Australia. Cluster analysis grouped women who had similar levels of risk based on health and lifestyle factors demonstrated to be associated with adverse maternal and infant outcomes. Interviews were conducted with 437 women. The results highlight the interconnectedness of demographic and health risks, and high concentration of risks among Indigenous women. Vulnerable women can be identified and targeted for public health interventions focussing on clustered risk factors, such as alcohol, smoking and sexually transmitted infections. Opportunity exists for screening in routine primary care to identify the individuals who are at risk, rather than identifying specific risks.